Congratulations!
I suggest you narrow down the optional choices to either Sabi Sabi (tres elegant and one of the premier safari places in South Africa) and Cape town/Table Mountain which are impressive as well. I guess for me would be the answer to: do you want to see more of the animals, or do you want to take in more of the city sights, museums, etc.? Look up some of the sights in CapeTown and see what interests you.